Brake mechanism for truck cranes



March 8, 1949. R. c. HOWELL BRAKE MECHANISM FOR TRUCK CRANES OriginalFiled Dec; 6, 1943 INVENTOR. Roy 6 Howe ll ATTORNEY Patented Mar. 8,1949 UNITED STATES PATENT OFFICE Original application December v6, 1943,Serial No. 513,204. Divided and this application August 31, 1945, SerialNo. 613,805

4 Qlaims. 1

This invention relates to a brake mechanism for motor truck cranes andthe like, the present application being a' division of my applicationSerial No. 513,204, filed December 6, 1943.

An important object of this invention is to provide a brake system inwhich the hoist and vehicle brakes may be so interconnected that thevehicle brakes are set during operation of the hoist and the hoistbrakes are set during travel of the vehicle.

A further object of the invention is to provide a simple control for thebrake control system by means of which one set of brakes may be lockedwhile the other set is operable at will and by which both sets of brakesmay be applied and locked when desired.

With the above and other objects in view, the invention may be said tocomprise the brake mechanism as illustrated in the accompanyingdrawings, hereinafter described and particularly set forth in theappended claims, together with such variations and modifications thereofas will be apparent to one skilled in the art to which the inventionpertains.

Reference should be had to the accompanying drawings forming a part ofthis specification in which the truck crane to which the invention isapplied is shown in outline in side elevation with the brake mechanismof the present invention thereon.

Referring to the accompanying drawings, the mechanism of the presentinvention is mounted upon a truck frame I supported at its forward endby traction wheels 2 provided with hydraulic brakes 3 of conventionalconstruction and at its rear end upon steering wheels 4. A turntable 5is mounted on the frame I to swing about a vertical axis positioned overthe axles of the front wheels 2, the turntable 5 having a boom 6, a boomhoist drum 1 controlled by a hydraulic brake 8 and a load hoist drum 9controlled by a hydraulic brake I0, the brakes 8 and I0 being applied toshafts that have a driving connection to the drums as is common practicein the art.

The present invention resides in the means employed for operating thewheel and drum brakes. As shown in the drawings, a brake pedal H mountedupon the frame I operates a piston l2 in a cylinder IS. The cylinder I3receives a liquid from a reservoir l4 through a lateral port and thepiston 12 when actuated by the pedal ll forces liquid under pressurethrough a pipe is to a cylinder I7 and through the cylinder l1 and apipe 1 8 to a valve casing 19 through which liquid may be delivered intoeither of two pipes 20 and 2| through which pressure is delivered to thedrum and wheel brakes. A two way valve 22 in the casing i9 is movable bymeans of a handle 23 from the neutral position shown in the draw ing toa position placing the pipe [8 in communication with the pipe 20 or to aposition connecting the pipe 18 to the pipe 2|. The pipe 20 deliversliquid under pressure to the hydraulic wheel brakes 3 and the pipe 25delivers liquid under pressure to the brakes 8 and Ill through a header24 mounted on the forward end of the truck frame I, a flexible conduit25 and a pipe 26 on the turntable 5 to which the flexible conduit 25delivers through a header 21 mounted on the turntable 5 adjacent thepivotal axis of the turntable, the pipe 26 being connected to thehydraulic brakes 8 and I0.

During propulsion of the motor truck the valve 22 is set in' theposition to connect the pipe 20 to the pipe l8 so that pressure will betransmitted through the pipe 20 leading to the wheel brakes uponactuation of the pedal ll. During hoisting operations the valve 22 ispositioned to deliver pressure through the pipe 2! to the drum brakes.If pressure is being applied either to the wheel or drum brakes when thevalve 22 is shifted, the pressure will be retained in such brakes afterthe valve is shifted because of the fact that the pressure is trappedbetween the brakes and the valve 22. By shifting the valve 22 while thewheel brakes are being applied, the wheel brakes may be set while thehoisting devices are being operated. By shifting the valve 22 while thewinding drum brakes 8 and I0 are being applied, the drum brakes may beset while the truck is traveling. If pressure be maintained in thecylinders 13 and I1 and the pipe l8 while the lever 23 is being shiftedto one extreme position to deliver pressure to the wheel brakes, andthen to the other extreme position to deliver pressure to the drumbrakes, and finally to neutral position, both the Wheel brakes and drumbrakes will be locked. It is ordinarily desirable that the wheel brakesbe set while the hoisting drums are being operated and that the hoistdrum brakes be set while the truck is traveling. Also when the truckframe is not in use, it is desirable that both the hoist brakes and thewheel brakes be set. The present invention provides a simple control forthe brakes by means of which these results can be accomnlished.

In order to apply an increased pressure either to the wheel brakes or tothe drum brakes when desired, a piston 28 is provided in the cylinderll. The piston 23 is normally held in retracted position by fluidpressure and carries a yieldably mounted valve 29 that is adapted toclose the port through which the pipes 16 deliver into the cylinder l1.Operation of the brake pedal ll forces liquid under pressure through thepipe l6 into the cylinder H and opens the valve 29. The piston 28 may beactuated to apply an increased pressure to the liquid forced through thevalve 22 by means of a lever 30 having a cam 3| bearing against thepiston 28. When the lever 30 is actuated the valve 29 is moved to closedposition and pressure is applied to the liquid in the cylinder l1 andthis pressure is transmitted to the brakes through the valve 22 and thepipe 20 or 2 l Actuating pressure may be applied to the liquid in thesystem by means of the piston 28 when the lever 30 is operatedindependently of the pedal H, or the lever 39 may be actuated while thepedal l I is depressed to hold the pressure and to apply additionalpressure.

It is to be understood that variations and modifications of the specificdevices herein shown and described for purposes of illustration, may bemade without departing from the spirit of the invention.

What I claim is:

1. In a machine of the character described a truck having hydraulicwheel brakes, a hoisting drum on said vehicle, a hydraulic brake forsaid drum, a pressure creating means on said truck, a valve casingconnected to said pressure creating means, a conduit connecting saidvalve casing with the wheel brakes, a separate conduit connecting saidvalve casing with the drum brake, and a valve in said casing movablefrom a position closing the drum brake conduit and connecting saidpressure creating means to the wheel brake conduit to a positionconnecting the pressure creating means to said drum brake conduit andclosing said wheel brake conduit.

2. In a machine of the character described a truck having hydraulicwheel brakes, a hoisting drum on said vehicle, a hydraulic brake forsaid drum, a pressure creating means on said truck, a valve casingconnected to said pressure creating means, a conduit connecting saidvalve casing with the wheel brakes. a separate conduit connecting saidvalve casing with the drum brake, and a valve in said casing movablefrom a position closing the drum brake conduit and .4 connecting saidpressure creating means to the wheel brake conduit to a positionconnecting the pressure creating means to said drum brake conduit andclosing said wheel brake conduit, said valve being so constructed as toclose both of said conduits when in an intermediate position.

3. In a, machine of the character described a truck having a hydraulicwheel brake, a hoisting drum on said vehicle, a hydraulic brake for saiddrum, a valve casing, separate conduits connecting said brakes to saidcasing, a liquid chamber, a conduit connecting said chamber to saidvalve casing, operator controlled means for creating a pressure in saidliquid chamber, and a manually operable valve in said valve casingmovable from a position closing the conduits to both of said brakes to aposition connecting the liquid chamber to the wheel brake conduit or toa position connecting the liquid chamber to the drum brake conduit, saidvalve being operable while pressure is being applied to either of thebrakes to close the conduit through which the pressure is beingtransmitted and set the brake.

4. In a machine of the character described a truck having a hydraulicwheel brake, a hoisting drum on said vehicle, a hydraulic brake for saiddrum, a valve casing, separate conduits connecting said brakes to saidcasing, a liquid chamber, a conduit connecting said chamber to saidvalve casing, operator controlled means for creating a pressure in saidliquid chamber, a manually operable valve in said valve casing forconnecting either of the brake conduits to said liquid chamber andsimultaneously closing the other, and a second pressure creating meansoperable independently of the first mentioned pressure creating meansupon the liquid in the conduit connecting said liquid chamber to saidvalve casing.

ROY C. HOWELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,248,676 Krausch et al Dec. 4,1917 2,233,192 Armington Feb. 25, 1941 2,254,083 Nickles et al Aug. 26,1941

